.glass {
        background: rgba(224, 224, 224, 0.3);
        backdrop-filter: blur(12px);
        -webkit-backdrop-filter: blur(12px);
        border: 1px solid rgba(70, 70, 70, 0.1);
      }

      .glass-light {
        background: rgba(164, 153, 153, 0.8);
        backdrop-filter: blur(12px);
        -webkit-backdrop-filter: blur(12px);
        border: 1px solid rgba(0, 0, 0, 0.6);
      }

      .gradient-bg {
        background: linear-gradient(-45deg, #ee7752, #e73c7e, #23a6d5, #23d5ab);
        background-size: 400% 400%;
        animation: gradient 15s ease infinite;
      }

      .skill-bar {
        position: relative;
        overflow: hidden;
      }

      .skill-progress {
        height: 100%;
        background: linear-gradient(90deg, #00bfff, #8b5cf6, #ec4899);
        border-radius: inherit;
        transform: translateX(-100%);
        transition: transform 2s ease-in-out;
      }

      .skill-progress.animate {
        transform: translateX(0);
      }

      .tech-icon {
        transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
        filter: grayscale(100%) brightness(0.8);
      }

      .skill-icon {
      width: 2.5rem;   /* ~40px */
      height: 2.5rem;
      font-size: 2.5rem;  /* cho FontAwesome */
      object-fit: contain; /* cho ảnh SVG */
    }

      .tech-icon:hover,
      .tech-icon:active {
        filter: grayscale(0%) brightness(1.2);
        transform: translateY(-10px) scale(1.1);
      }

      .project-card {
        transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
        position: relative;
        overflow: hidden;
      }

      .project-card::before {
        content: "";
        position: absolute;
        top: 0;
        left: -100%;
        width: 100%;
        height: 100%;
        background: linear-gradient(
          90deg,
          transparent,
          rgba(255, 255, 255, 0.1),
          transparent
        );
        transition: left 0.5s;
      }

      .project-card:hover::before,
      .project-card:active::before {
        left: 100%;
      }

      .project-card:hover,
      .project-card:active {
        transform: translateY(-10px) scale(1.02);
      }

      .floating-label {
        transition: all 0.3s ease;
        pointer-events: none;
      }

      .form-input:focus + .floating-label,
      .form-input:not(:placeholder-shown) + .floating-label {
        transform: translateY(-25px) scale(0.8);
        color: #00bfff;
      }

      .certificate-card {
        transition: all 0.3s ease;
        position: relative;
        overflow: hidden;
      }

      .certificate-card:hover,
      .certificate-card:active {
        transform: translateY(-5px) rotateY(5deg);
      }

      .testimonial-card {
        transition: all 0.3s ease;
        height: 100%;
        display: flex;
        flex-direction: column;
      }

      .testimonial-card:hover,
      .testimonial-card:active {
        transform: scale(1.05);
      }

      .testimonial-content {
        flex-grow: 1;
      }

      /* GitHub Activity - TIDAK DIUBAH */
      .github-activity {
        display: grid;
        grid-template-columns: repeat(53, 1fr);
        gap: 2px;
        max-width: 100%;
        overflow-x: auto;
      }

      .activity-day {
        width: 10px;
        height: 10px;
        border-radius: 2px;
        transition: all 0.2s ease;
        min-width: 10px;
      }

      .activity-day:hover {
        transform: scale(1.5);
      }

      .activity-0 {
        background-color: #161b22;
      }
      .activity-1 {
        background-color: #0e4429;
      }
      .activity-2 {
        background-color: #006d32;
      }
      .activity-3 {
        background-color: #26a641;
      }
      .activity-4 {
        background-color: #39d353;
      }

      /* Responsive Grid Fixes - TIDAK DIUBAH */
      @media (max-width: 768px) {
        .github-activity {
          grid-template-columns: repeat(26, 1fr);
        }

        .activity-day {
          width: 8px;
          height: 8px;
          min-width: 8px;
        }
      }

      .modal {
        display: none;
        position: fixed;
        z-index: 1000;
        left: 0;
        top: 0;
        width: 100%;
        height: 100%;
        background-color: rgba(0, 0, 0, 0.8);
        backdrop-filter: blur(5px);
      }

      .modal.show {
        display: flex;
        align-items: center;
        justify-content: center;
        animation: fadeIn 0.3s ease-out;
      }

      .modal-content {
        background: rgba(26, 26, 46, 0.95);
        backdrop-filter: blur(20px);
        border: 1px solid rgba(255, 255, 255, 0.1);
        border-radius: 16px;
        padding: 2rem;
        max-width: 500px;
        width: 90%;
        max-height: 90vh;
        overflow-y: auto;
        animation: scaleIn 0.3s ease-out;
        margin: 1rem;
      }

      @media (max-width: 640px) {
        .modal-content {
          padding: 1.5rem;
          margin: 0.5rem;
        }
      }

      .star-rating {
        display: flex;
        gap: 4px;
        margin: 8px 0;
      }

      .star {
        font-size: 20px;
        color: #374151;
        cursor: pointer;
        transition: color 0.2s ease;
        min-height: 44px;
        min-width: 44px;
        display: flex;
        align-items: center;
        justify-content: center;
        -webkit-tap-highlight-color: transparent;
      }

      .star:hover,
      .star:active,
      .star.active {
        color: #fbbf24;
      }

      /* FIXED: Better spacing for cards with mobile support */
      .card-grid {
        display: grid;
        gap: 1.5rem;
        width: 100%;
      }

      /* Mobile First Approach */
      .card-grid.cols-1,
      .card-grid.cols-2,
      .card-grid.cols-3,
      .card-grid.cols-4 {
        grid-template-columns: 1fr;
      }

      /* Tablet */
      @media (min-width: 640px) {
        .card-grid {
          gap: 2rem;
        }
        
        .card-grid.cols-2,
        .card-grid.cols-3,
        .card-grid.cols-4 {
          grid-template-columns: repeat(2, 1fr);
        }
      }

      /* Desktop */
      @media (min-width: 1024px) {
        .card-grid.cols-3 {
          grid-template-columns: repeat(3, 1fr);
        }
        
        .card-grid.cols-4 {
          grid-template-columns: repeat(4, 1fr);
        }
      }

      /* FIXED: Enhanced Skills Section with Mobile Support */
      .skills-grid {
        display: grid;
        grid-template-columns: repeat(2, 1fr);
        gap: 1rem;
        justify-items: center;
        align-items: start;
      }

      @media (min-width: 480px) {
        .skills-grid {
          grid-template-columns: repeat(3, 1fr);
          gap: 1.5rem;
        }
      }

      @media (min-width: 640px) {
        .skills-grid {
          grid-template-columns: repeat(4, 1fr);
        }
      }

      @media (min-width: 768px) {
        .skills-grid {
          grid-template-columns: repeat(5, 1fr);
          gap: 2rem;
        }
      }

      @media (min-width: 1024px) {
        .skills-grid {
          grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
        }
      }

      .skill-card {
        background: rgb(255, 255, 255);
        border: black;
        backdrop-filter: blur(10px);
        border: 1px solid rgba(255, 255, 255, 0.1);
        border-radius: 16px;
        padding: 1rem;
        width: 100%;
        max-width: 140px;
        text-align: center;
        transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
        position: relative;
        overflow: hidden;
        -webkit-tap-highlight-color: transparent;
      }

      @media (min-width: 640px) {
        .skill-card {
          padding: 1.5rem;
        }
      }

      .skill-card:hover,
      .skill-card:active {
        transform: translateY(-10px) scale(1.05);
        box-shadow: 0 20px 40px rgba(0, 191, 255, 0.3);
        border-color: rgba(0, 191, 255, 0.5);
      }

      .skill-card::before {
        content: "";
        position: absolute;
        top: 0;
        left: -100%;
        width: 100%;
        height: 100%;
        background: linear-gradient(
          90deg,
          transparent,
          rgba(255, 255, 255, 0.1),
          transparent
        );
        transition: left 0.6s;
      }

      .skill-card:hover::before,
      .skill-card:active::before {
        left: 100%;
      }

      .skill-icon-wrapper {
        width: 50px;
        height: 50px;
        margin: 0 auto 0.75rem;
        border-radius: 50%;
        display: flex;
        align-items: center;
        justify-content: center;
        position: relative;
        overflow: hidden;
      }

      @media (min-width: 640px) {
        .skill-icon-wrapper {
          width: 60px;
          height: 60px;
          margin: 0 auto 1rem;
        }
      }

      .skill-icon {
        font-size: 1.5rem;
        color: rgb(0, 0, 0);
        z-index: 2;
        position: relative;
      }

      @media (min-width: 640px) {
        .skill-icon {
          font-size: 2rem;
        }
      }

      .skill-name {
        font-size: 0.75rem;
        font-weight: 600;
        margin-bottom: 0.5rem;
        color: #e5e7eb;
      }

      @media (min-width: 640px) {
        .skill-name {
          font-size: 0.875rem;
        }
      }

      .skill-level {
        width: 100%;
        height: 4px;
        background: rgba(255, 255, 255, 0.1);
        border-radius: 2px;
        overflow: hidden;
        position: relative;
      }

      .skill-level-fill {
        height: 100%;
        background: linear-gradient(90deg, #00bfff, #8b5cf6);
        border-radius: 2px;
        transform: translateX(-100%);
        transition: transform 1.5s ease-out;
      }

      .skill-level-fill.animate {
        transform: translateX(0);
      }

      /* Touch-friendly improvements */
      @media (hover: none) and (pointer: coarse) {
        .skill-card:active,
        .project-card:active,
        .certificate-card:active,
        .testimonial-card:active {
          transform: scale(0.98);
        }
      }

      /* Ensure proper touch targets */
      button, .skill-card, .project-card, .certificate-card, .testimonial-card {
        min-height: 44px;
        min-width: 44px;
      }